env: Add CONFIG_SYS_RELOC_GD_ENV_ADDR symbol

Today in initr_reloc_global_data() we use some non-obvious tests to
determine if we need to relocate the env_addr within gd or not.  In
order to facilitate migration of other symbols to Kconfig we need to
introduce a new symbol for this particular use case.

Cc: Wolfgang Denk <wd@denx.de>
Cc: Joe Hershberger <joe.hershberger@ni.com>
Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/sama5d4_xplained_mmc_defconfig b/configs/sama5d4_xplained_mmc_defconfig
index bba6c63..9956bf1 100644
--- a/configs/sama5d4_xplained_mmc_defconfig
+++ b/configs/sama5d4_xplained_mmc_defconfig
@@ -44,6 +44,7 @@
 CONFIG_DEFAULT_DEVICE_TREE="at91-sama5d4_xplained"
 CONFIG_OF_SPL_REMOVE_PROPS="interrupts interrupt-parent dma-names dmas"
 CONFIG_ENV_IS_IN_FAT=y
+CONFIG_SYS_RELOC_GD_ENV_ADDR=y
 CONFIG_DM=y
 CONFIG_SPL_DM=y
 CONFIG_CLK=y